[bobnjieun]

Newbie with a pretty stupid mechanical question.

I changed the front sprocket to the 14Tooth, put everything back together and now my clutch doesn't engage. I can drop it in gear but the bike doesn't move when I let out the clutch. It's also 3 times harder to pull in the clutch lever.

I'm guessing it has to do with the clutch slave cylinder that I had to remove to get the front sprocket off/on but why doesn't it go into gear. Never had a bike with a wet clutch so I'm quite baffled. I guess it doesn't help that I'm a mechanically naive either I have a 2010 Hyper 796 with only 2,900 miles

 

[acropilot]

they have a rod that the slave cyl.works to acuate the clutch pull the slave back off and check the rod and make sure it's not hung up

 

[bobnjieun]

Ok, thanks acro. I pulled the rod out, saw the oil in there and quickly reinserted it. Does the rod have to be pushed in a certain distance or does it go back in place when I tighten the 3 screws? I guess I'm not understanding what "hung up" means.

 

[acropilot]

well it should go in almost all the way and then put the slave in place and you should be able to push it flush to the case by hand before tightening the bolts

 

[bobnjieun]

ok, thanks. When I tried to push the slave back on, it would not go flush until I tightened the bolts. There must be something causing it from seating flush but that's strange because it was never pulled out during the removal. I wonder if the oil in there caused it to come out a bit. I'll disassemble again and see what's up. Thanks acro!

 

[vb1100sp]

There's a black plastic piece inside there that might have something to do with it. I'm not sure what it does though . I'm sure someone will chime in


Sent from my iPhone using Motorcycle

 

[johnchypermotard]

also suggest that you bleed the clutch line, both from the slave end, and then from the master cylinder top bleed nipple. make sure to bleed slowly, and get all the air bubbles out.

 

[el tardo]

what it sounds like to me is the clutch lever got pulled in while you had the slave off the bike. its ok it happens to the best of us.

easy fix is to bleed it.if its a 796 your best bet is to use a vacuum bleeder.a 796 doesnt have a way to bleed it at the master. the clutch line threads directly into the master. i know cause i have one.wont take more the two minutes to do.

 

[bobnjieun]

Thanks all for the advice! So to "bleed" it, does that mean I have to remove all the oil and then refill it? Can you tell me where to get a vacuum bleeder?

 

[HyperDuc796]

You need to take it to someone that knows what they are doing, cause you have done enough damage already.

 

[rdeppen]

I hate to say it but if your not familiar with how to bleed a hydraulic brake or in your case master cylinder you need to get someone to help you. It's not hard at all and a good mighty vac tool can be had for under $40 at any harbor freight. It needs to be done in a specific process to get it right thou. Search YouTube for how to bleed a Ducati hydraulic clutch and decided if you want to tackle it yourself. Theres a good video of the process on a Superbike there


Sent from my Motorcycle iPhone app

 

[johnchypermotard]

You need to take it to someone that knows what they are doing, cause you have done enough damage already.

that's pretty cold shit, and as a fellow canadian, i want to apologize for that reply.

you can bleed the clutch yourself... not too difficult to do if you have the right tools and some patients. and FWIW, i hate using a bleed tool, unless it is the really expensive all metal ones that shops have ... the plastic ones that you can find in stores usually are not worth the money, as they tend to leak and bleed air into the system, imho.

so, for the above reason, i tend to go old school and use a clear plastic hose, a catch can, some shop rags and the appropriate wrenches to open/close the bleed nipples.


you will need the correct sized open ended wrenches to open the bleed valve nipples on the master and the slave. you will also need about 3 feet of the appropriate sized clear plastic hose (make sure it can handle clutch fluid), and a can to catch the bled fluid into. some shop towels are also a great idea, to catch any fluid before it hits painted parts. and finally, you will need some new brake fluid. depending on how old the fluid that's in the system is, you might not need to completely flush the system, but as fluid is cheap, you might as well completely flush it when you bleed the system. new fluid is always good.

the fluid brand you select is up to you .... i bet you will get as many opinions on brands of brake fluid as you will on brands of oil to use. just make certain it is the same type or a compatible type fluid. check your manual to make certain. on my 2008 hyper 1100 the owners manual suggests shell advance DOT 4. i use ATE super blue DOT 4


i always start bleeding (and certainly flushing) with the slave cylinder, as it is the lowest point in the system.

1. remove the cap from the reservoir.

2. pull the rubber cap off the slave nipple, place the hose over the nipple and the other end of the clear hose into the catch can.

3. if you have a friend who can assist, this is the time to have them lend a hand. have them slowly pul the clutch lever in a few times, then on an agreed pull, you loosen the nipple enough, so when they are pulling the lever in, the fluid (and hopefully bubbles) start coming out through the hose. it is CRITICAL that they pull the lever slowly, and when they have the lever pulled in all the way to the bar, they keep the lever tight against the bar and you tighten the bleed valve, so that no fluid/air gets back into the slave. DO NOT over tighten the nut. snug is good. stripped is bad.

4. if you are going to fully flush the system, complete the same procedure as many times as required, until the fluid that is coming out of the bleed valve into the hose is clean and clear in color.

5. keep an eye on the reservoir fluid level, and top up as required when you are flushing/bleeding the system. DO NOT let the fluid get so low as to allow air to get sucked into the system.

6. once you have the system flushed completely, you can tighten the slave bleed valve completely (again, DO NOT over tighten), and replace the rubber cap.


now you move up to the master cylinder (if your 796 has a bleeder on the master... i don;t have access to a 796 right now, so don't know for sure).

1. remove the rubber cap off the bleed valve, and place the correct sized wrench on the bleed valve nut.

2. place the clear hose over the bleed nipple, and the other end into the catch can (you might need to use a table or step stool to rest the catch can on). this is where shop towels are good to have, to place over the tank shroud on the left side, and on top pf the front fender, under the master cylinder, just in case you spill some fluid when filling the reservoir.

3. it's the same procedure for bleeding the master cylinder as the slave ... pull the lever in SLOWLY a few times, then on an agreed upon pull, open the bleed valve to let the air bubbles and fluid come out. again, make sure to hold the lever tight against the bar on the pull that you open the bleed nipple, and close the bleed nipple when the lever is held tight, not allowing air/fluid back into the system.

4. it usually takes two or three bleeds of the master to get all the air bubbles out. take your time, and make sure there are not any bubbles coming out before you stop.

your clutch will really feel much better after doing a flush/bleed, so it is well worth the time and effort required for the task.

you will know when it is time to flush the system again, when the fluid in the reservoir turns from clear to a darker color.

for what little brake fluid costs, and the time required to do a flush, it's money and time well spent to keep the clutch hydraulics system clean and functioning well.

hope this helps.

if i have left anything out, i am sure someone will add the correction(s).

ciao,
johnc

 

[vb1100sp]

Very well written , I'll save this for myself .


Sent from my iPhone using Motorcycle

 

[vroooom]

You wouldn't happen to have aftermarket levers would you? The reason I'm asking is because this kinda happened to me and someone told me that it might be the lever and the rod applying pressure inside. I'm not totally convinced at this point because mine ran for 2000kms without any problem until recently and after the shop bled the system it seems to be working fine now. However I'm not ruling that out and it's still under observation at this point. I haven't been able to take the bike out coz it has been raining like crazy every weekend.

You have a 796. I also do. I don't think you need that "bleed from the master" portion. Correct me if I'm wrong pls. You will be bleeding with the reservoir open and open nipple-squeeze lever-close nipple-release lever. Squeeze the lever a couple of times ...kinda like building some pressure in the line before each opening of the nipple. Just remove that cover but keep the rubber cover/gasket on the reservoir. If you do not, you'll quickly discover that it will be squirting fluid all over your plastic side fairing so keep that on top. Make sure you keep the fluid "full" as per the previous post. I said "full" because it's not really full to the brim.... The gasket's triangular portion takes up some room in the reservoir. Just keep monitoring the fluid level so you don't pump and introduce air into the system. Have some alcohol handy. Spray and wipe the spilled brake fluid with that ASAP since its caustic to the paint. Do not let the fluid drip to the brake calipers. Rags come in handy. That's it. Like what John said... Don't over tighten the nipple. Snug enough but don't crank on it like a gorilla. Of course you do this with your slave installed. Good luck.

Non-res CDN here. You're in Cupertino John. Non-res also?

 

[bobnjieun]

Thanks again for the advice, especially to Johnc and Vroom. I would normally just take the bike in to the nearest dealer but they are 60 miles away and I would have to call a tow truck to get the bike there. I think I can accomlplish this with your detailed instructions, so thank you very much! I'm thankful for forums and people like you!

 

[bobnjieun]

You wouldn't happen to have aftermarket levers would you?

BTW I do have aftermarket levers. Thinking back on the entire process, I don't recall pulling the clutch lever in when the slave was off the bike. I just followed the procedures in the service manual but I did notice that the slave was not flush as I was reassembling. You might be onto something.

 

[el tardo]

more help. the 796 with its cheap brembo master is not like bleeding brakes or other clutch masters. this bike is very hard due to the air that gets trapped in the master.this bike has no way to bleed at the top which makes normal bleeding skills worthless.

this bike has to be vacuum bled cause of that reason above. the trick to vacuum bleeding is you must remove the bleeder screw and wrap it with Teflon tape. the tape must be done cause once you add vacuum and break open the bleeder the bleeder screw will suck in air around the threads and it will never work right. this is also why 99% of most people dont know how to use a vacuum bleeder.

second note just for most of you clutch bleeding and brakes work different.on a clutch ,the clutch rod pushes back while bleeding making it very hard to all air out and a firm lever,brakes dont work this way.they dont have a clutch rod beaning pushed back by clutch springs.

and again, it should only take about two minutes to fix your problem.

hope this clears the air about vacuum bleeding-------------------------

 

[vroooom]

did you install that aftermarket during the same time you installed the 14t sprocket? if so then go back and install the stock again and see. like i said mine ran with the aftermarket levers for ~2000kms before it had that issue that's why i said i'm not totally convinced it is the lever in my case.... but i'm not ruling it out either. mine also became harder to pull and it felt "rough" as if i needed grease on the pivot.

if you did install them at the same time then that might be your issue. as you know the clutch has to have some play or looseness in the initial travel. you don't want it engaged. i've read that the rod needs to be shorten.

 

[vroooom]

el tardo,

can you clarify that statement on the air being trapped on the master/reservoir?

also the problem with removing that nipple in order to apply the teflon, you will now really end up introducing air all over the line since most of the fluid will run out of the hose, noh? unless you plug it with your finger while you have a friend do the teflon and make sure the reservoir is never out of fluid. also as long as you have enough vacuum in the canister, wouldn't the air being introduced through that area mentioned just continuously go inside the canister with the flow of the fluid? it wouldn't actually go up the line. again as long as there's vacuum in the canister.

would love to know more about that clutch slave and how it works. i thought it works almost like the brakes as in the pushrod moves out (pushed) off the slave as the lever is pulled towards the bar. that action pushes the clutch plate apart (disengaged). is that not right? theoretically, if your hose develops a leak and all your fluid is spilled, what would the clutch be on.... will it not be engaged (stuck on one gear as default) or disengaged (engine runs but bike does not move)? i'm asking this because the issue from the OP says the bike does NOT move. shouldn't the bike be stuck in a gear and should move as long as it's not stuck in N. if there's a leak or air in the system then shouldn't the lever be really easy to pull and feel spongy and soft? That's why I couldn't understand why bleeding would work but it did work when the shop did it on my bike.

fyi: not questioning your statement.... just asking questions coz i really want to understand as i'm having the same issue and i'm not understanding how the bleeding solved it. my mileage is about the same as the OP's too but the issue only appeared recently and only after riding it for 20 mins or so.

 

[rdeppen]

That is the video I referenced last night. I strongly disagree with not using a mighty vac tool to bleed a clutch slave. You can't build the same pressure to force the fluid through as well as doing brakes. It can be done that way but with a tool it's a 10 minute process. Dont buy the cheap one get a mighty vac brand tool.

My question would be how does air get introduced into the system and need a bleed if all he did was unbolt it from the bike? If the bleeder was never cracked how does air get in? I'd be looking more at the aftermarket levers myself.